From: Gerd Hoffmann <kraxel@redhat.com>
Date: Fri, 13 Mar 2020 12:35:26 +0000 (+0000)
Subject: Add exit notifiers.
X-Git-Tag: xen-4.14.0~1
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=eb9bf793f5857ab5ca850bfecba4f11496881500;p=qemu-xen-unstable.git

Add exit notifiers.

Hook up any cleanup work which needs to be done here.  Advantages over
using atexit(3):

  (1) You get passed in a pointer to the notifier.  If you embed that
      into your state struct you can use container_of() to get get your
      state info.
  (2) You can unregister, say when un-plugging a device.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit fd42deeb4cb42f90084046e3ebdb4383953195e3)
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---

diff --git a/sysemu.h b/sysemu.h
index 968258a841..759d0e9d53 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -2,6 +2,8 @@
 #define SYSEMU_H
 /* Misc. things related to the system emulator.  */
 
+#include "notify.h"
+
 /* vl.c */
 extern const char *bios_name;
 extern const char *bios_dir;
@@ -39,6 +41,9 @@ void qemu_system_powerdown(void);
 #endif
 void qemu_system_reset(void);
 
+void qemu_add_exit_notifier(Notifier *notify);
+void qemu_remove_exit_notifier(Notifier *notify);
+
 void do_savevm(const char *name);
 void do_loadvm(const char *name);
 void do_delvm(const char *name);
diff --git a/vl.c b/vl.c
index c3c5d630e8..2163217ec7 100644
--- a/vl.c
+++ b/vl.c
@@ -282,6 +282,9 @@ uint8_t qemu_uuid[16];
 
 #include "xen-vl-extra.c"
 
+static NotifierList exit_notifiers =
+    NOTIFIER_LIST_INITIALIZER(exit_notifiers);
+
 /***********************************************************/
 /* x86 ISA bus support */
 
@@ -4843,6 +4846,21 @@ static void vcpu_hex_str_to_bitmap(const char *optarg)
     }
 }
 
+void qemu_add_exit_notifier(Notifier *notify)
+{
+    notifier_list_add(&exit_notifiers, notify);
+}
+
+void qemu_remove_exit_notifier(Notifier *notify)
+{
+    notifier_list_remove(notify);
+}
+
+static void qemu_run_exit_notifiers(void)
+{
+    notifier_list_notify(&exit_notifiers);
+}
+
 int main(int argc, char **argv, char **envp)
 {
 #ifdef CONFIG_GDBSTUB
@@ -4887,6 +4905,8 @@ int main(int argc, char **argv, char **envp)
     const char *chroot_dir = NULL;
     const char *run_as = NULL;
 
+    atexit(qemu_run_exit_notifiers);
+
     qemu_cache_utils_init(envp);
     logfile = stderr; /* initial value */